The field of the present invention is vehicle axles of the type employing a friction clutch for differential drive.
Small vehicles, carts and the like driven by power directed to an axle for distribution to parallel wheels at the ends of the axle can exhibit handling difficulty and excessive tire wear if the axle is solid, without differential capability. Differential gearing and ratchet type differentials have been available to accommodate the need for unequal wheel velocity for negotiating turns. However, on vehicles intended to be used or expected to encounter off-road or highly variable friction conditions, such devices tend to direct power unequally to the unloaded wheel. Consequently, more complicated differential systems, limited slip differentials, have been employed.
In smaller vehicles, the use of complicated differential and limited slip differential devices is generally impractical because of the complexity, size and/or cost of such systems. As a result, simplier differential devices employing a friction clutch to give resisted slip differential capability have been employed.
The use of a friction clutch for differential capability requires the selection of a specific response to input torque to the axle. Under road conditions, a relatively light clutch action may be advantageous to allow accommodation of lower torque differential action in making a turn. Under high torque conditions, for example, in off-road high performance usage, greater torque transmitting capabilities through the differential clutch are desirable. Consequently, a compromise design has generally been required of such systems to accommodate a broad range of operating conditions.